This invention relates to an excavating tooth and, more particularly, one in which an assembly consisting of a point, adapter and wear cap has a unique stabilizing relationship between the elements so as to resist heavy forces.
As such, it is an improvement upon the co-owned application of Robert K. Emrich, Ser. No. 173,769, filed July 30, 1980, now U.S. Pat. No. 4,326,348. In that case, a unique stabilization was developed between the three elements utilizing side tongues on the wear cap engaging recesses at the point rear sides. Inasmuch as this invention is an improvement thereon, specific reference may be made thereto for details not herein given, and for that purpose, express reference is made thereto.
Although removable points have been used for years to save on throw-away metal when the bit end of the tooth becomes worn and unrepairable, and notwithstanding the fact that wear caps have also been used for a long time to preserve the adapters, it was not until the appearance of the above-identified co-owned application that a unique cooperation was developed between the point and wear cap. The stabilization involved, derives from U.S. Pat. No. 3,079,710 which provided longitudinally spaced apart beam bearing surfaces so as to successfully resist beam forces tending to "wipe" the point off of the adapter. This stabilization is particularly important where the point is relatively short as is the case with huge shovel dippers and drag line buckets.
According to the invention, a novel cooperation is provided between the wear cap and point wherein these two elements function to provide secondary stabilization in the manner of the above-identified application but with different elements. In the preferred embodiment, the wear cap is equipped with a recessed forward edge which mates with a correspondingly contoured recess in the point rear portion and which serve the purpose of secondary stabilization. More particularly, the instant invention has a point wherein the rear portion thereof is equipped with a step to provide a rearwardly-extending integral flange so as to develop two advantages from the single change. First, the point flange in combination with the overlying portion of the wear cap provides secondary stabilization, particularly against the ever-present beam loads tending to "wipe" the point off the adapter. Second, the point flange is positioned in protected relation relative to the projecting forwardly extending flange of the wear cap. This insures that the point flange is not subject to wear and is thereby able to continue the first function throughout its wear life.